Grinding machines whose tools and/or grinding wheels are movable about several theoretical axes are known in practice. When a peripheral milling cutter has to be ground with such grinding machines, the customary procedure is to first cut a continuous chipping-groove in the shaft portion , and then--after disengaging the grinding wheel--to cut the chipping-groove in the hemispherical end by means of successive plunging cuts. This necessarily results in the cutting edge in the hemispherical end having a polygonal course, which is undesirable because it results in the milled surface being polygonal as well instead of cylindrical. Apart from that, the interruption of the grinding process while moving from the shaft portion to the hemispherical end portion causes a ridge that prevents formation of a smooth continuity of the cutting edge.
Peripheral milling cutters with better contours are produced by means of grinding with templates which in fact result in a more or less ideal cutting edge. However, with this type of grinding, precision leaves something to be desired.
Particular difficulties arise when the milling cutter is to have a positive rake in the hemispherical end as well.